$$$\sin{\left(\phi \right)}$$$の積分

$$$\int \sin{\left(\phi \right)}\, d\phi$$$ を求めよ。

正弦関数の不定積分は$$$\int{\sin{\left(\phi \right)} d \phi} = - \cos{\left(\phi \right)}$$$です:

$${\color{red}{\int{\sin{\left(\phi \right)} d \phi}}} = {\color{red}{\left(- \cos{\left(\phi \right)}\right)}}$$

したがって、

$$\int{\sin{\left(\phi \right)} d \phi} = - \cos{\left(\phi \right)}$$

積分定数を加える:

$$\int{\sin{\left(\phi \right)} d \phi} = - \cos{\left(\phi \right)}+C$$

$$$\int \sin{\left(\phi \right)}\, d\phi = - \cos{\left(\phi \right)} + C$$$A